Answer:
B will be the answer...
Step-by-step explanation:
The second equation in system B is only in terms of y, so we need to use elimination to eliminate the x term from the second equation in system A.
To do that, we need to multiply the first equation by 5.
5 (-x − 2y = 7)
-5x − 10y = 35
Add to the second equation. Notice the x terms cancel out.
(-5x − 10y) + (5x − 6y) = 35 + (-3)
-16y = 32
Combining this new equation with the first equation from system A will get us system B.
-x − 2y = 7
-16y = 32
Given that
(2/x)+(3/y) = 13--------(1)
(5/x)-(4/y) = -2 -------(2)
Put 1/x = a and 1/y = b then
2a + 3b = 13 ----------(3)
On multiplying with 5 then
10a +15 b = 65 -------(4)
and
5a -4b= -2 ----------(5)
On multiplying with 2 then
10 a - 8b = -4 -------(6)
On Subtracting (6) from (4) then
10a + 15b = 65
10a - 8b = -4
(-)
_____________
0 + 23 b = 69
______________
⇛ 23b = 69
⇛ b = 69/23
⇛ b =3
On Substituting the value of b in (5)
5a -4b= -2
⇛ 5a -4(3) = -2
⇛ 5a -12 = -2
⇛ 5a = -2+12
⇛ 5a = 10
⇛ a = 10/5
⇛ a = 2
Now we have
a = 2
⇛1/x = 2
⇛ x = 1/2
and
b = 3
⇛1/y = 3
⇛ y = 1/3
<u>Answer :-</u>The solution for the given problem is (1/2,1/3)
<u>Check</u>: If x = 1/2 and y = 1/3 then
LHS = (2/x)+(3/y)
= 2/(1/2)+3/(1/3)
= (2×2)+(3×3)
= 4+9
= 13
= RHS
LHS=RHS is true
and
LHS=(5/x)-(4/y)
⇛ 5/(1/2)- 4/(1/3)
⇛(5×2)-(4×3)
⇛ 10-12
⇛ -2
⇛RHS
LHS = RHS is true
Answer:
4/7
Step-by-step explanation:
Number of Blue vans = 4
Number of white vans = 3
Total number of vans = Number of Blue vans + Number of white vans
= 4 + 3
= 7 vans
Number of blue vans : Number of white vans = 4 : 3
Fraction of vans that are blue = Number of Blue vans / Total number of vans
= 4 / 7
Fraction of vans that are blue = 4/7
Answer:
Part A:
The probability that all of the balls selected are white:

Part B:
The conditional probability that the die landed on 3 if all the balls selected are white:

Step-by-step explanation:
A is the event all balls are white.
D_i is the dice outcome.
Sine the die is fair:
for i∈{1,2,3,4,5,6}
In case of 10 black and 5 white balls:






Part A:
The probability that all of the balls selected are white:


Part B:
The conditional probability that the die landed on 3 if all the balls selected are white:
We have to find 
The data required is calculated above:

X = original amount of water
x - 8(6) = 132
x - 48 = 132
x = 132 + 48
x = 180...it originally contained 180 gallons